A pneumatic tire is generally provided with a bead apex C between the carcass A and its turned up portion B in each bead portion as shown in FIG. 4. A bead apex is made of hard rubber (for example JIS A hardness of 60 to 90) to increase the bending rigidity of the bead portion and sidewall lower portion, thereby improving the steering stability. However, recent high performance ears require further improved tire performance. A tire weight reduction is one way to improve tire performance. In order to reduce the tire weight, for example, if the tread rubber volume is decreased, the road grip and wear life are decreased. If the sidewall rubber volume is decreased, reinforcement cord layers, e.g. the carcass are liable to be damaged. Therefore, it is difficult to employ those means.
It is therefore, an object of the present invention to provide a pneumatic tire, in which a tire weight reduction is achieved while the other tire performance is maintained or improved.